<!doctype html>
<html>

	<head>
		<meta charset="UTF-8">
		<title></title>
		<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1,maximum-scale=1,user-scalable=no" />
		<style>
			.box {
				width: 100px;
				height: 100px;
			}

			.bg {
				background: linear-gradient(90deg, #f2f2f2 25%, #e6e6e6 37%, #f2f2f2 63%);
				background-size: 400% 400%
			}

			.active {
				animation: loading 1.4s ease infinite
			}

			@keyframes loading {
				0% {
					background-position: 100% 50%
				}

				100% {
					background-position: 0 50%
				}
			}
		</style>
	</head>
	<body>
		<div class="box bg active"></div>
	</body>
</html>
